The effect of pharmacologic agents on the modulation of spontaneous uterine activity and on the diurnal variations of the dynamics of the pregnant uterus will be evaluted in monkeys. The studies will be directed toward pharmacological suppression and augmentation of endogenous prostaglandins. The effect of these procedures will be studied in the intact animal and following selective blocking of adrenergic alpha and beta receptors, distruction of postganglionic sympathetic nerve endings and pharmacologic suppression of norepinephrine and epinephrine. Chronically implanted sensors will monitor intrauterine pressure, uterine blood flows, arterial and venous blood pressures, and body temperature. Electronic integration and computer analysis of measured parameters will facilitate evaluation of the studies in an effort to elucidate some of the factors involved in the physiology and control of myometrial contractility. A primate breeding colony will be maintained. BIBLIOGRAPHIC REFERENCE: Johnson, W. L., Harbert, G. M., and Martin, C. B., Pharmacologic Control of Uterine Contractility, Amer. J. Obstet. Gynec. 123:364,1975.